Calender nip control device



Nov. 24, 1964 K. H. SEIDEL 3,158,038

CALENDER NIP CONTROL DEVICE Filed July 11, 1965 2 Sheets-Sheet 1 Eg-j I i llllll INVENTOR.

Me /Z 69/2/61 a1 O w nj A TTOR Nov. 24, 1964; K s EL 3,158,088

CALENDER NIP CONTROL DEVICE Filed July 11, 19466 2 Sheets-Sheet 22 a! so as 29 as 2e 2e a. I 1 3 mm L, 24 q 26 k 29 3 36 INVENTOR.

ATTORNEYS United States Patent 3,158,988 Ni? CGNTEEL BEVECE Karl H. eidel, Eeioit, Wis, assignor to Beioit Corporation, Eeloit, Wis, a corporation of Wisconsin Filed .iniy llll, 1963, Ser. No. 294,337 9 Qlaims. (El. lilo-163) This invention relates to improvements in paper making machines and more particularly relates to an improved form of calender stack for use in such machines.

Calender stacks for calendering or ironing paper and the like comprise a stack of calender rolls which may be formed from fine grain cast iron and a bottom hard surfaced finishing roll, commonly called a king roll. In all calender stacks it is desirable to raise the rolls out of engagement with each other at the termination of a calendering operation, to accommodate cooling of the calender rolls and to thereby prevent warping thereof and to accommodate a new web to be threaded through the stack. It is also desirable to relieve the rolls from the weight of the supporting bearings therefor, to thereby reduce the pressure between the nips of the stack of rolls and to increase the nip pressures when desired.

Due to mechanical difficulties, such as interference between the roll raising mechanism and the nip pressure varying mechanism it has not been possible to economically provide a means associated with the support for the calender rolls, which will both increase and relieve the nip pressure between the rolls and will also accommodate the calender rolls to be freely raised out of contact with each other at the termination of a calendering operation.

The present invention has at its objects to remedy the foregoing disadvantages in calender stacks by providing a simple and novel form of mechanism for relieving or increasing nip pressures, which will not interfere with free raising of the rolls out of engagement with each other.

Another object of the invention is to provide a simple and improved form of calender stack in which the rolls may be freely raised out of engagement with each other and the nip pressures may be relieved or increased during the calendering operation.

Still another object of the invention is to provide a novel and improved form of calender stack having a roll raising mechanism independent of the mechanism for varying the nip pressures, and so arranged as to avoid the interferences heretofore present in such machines and accommodate free raising of the calendering rolls with out interfering with the mechanism for varying the nip pressures.

A further and important object of the invention is to provide an improved form of multi-nip calender comprising a calender frame, a series of vertically spaced lifting arms for supporting the rolls in the frame, mechanism for operating the lifting arms to lift the calender rolls out of engagement with each other and fluid operative mechanism for increasing or relieving the nip pressures independently of the roll raising mechanism and camrned by the lifting arms to accommodate free lifting of the arms during the operation of lifting the rolls out of engagement with each other.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

FIGURE '1 is a side elevational view of a calender stack constructed in accordance with the principles of the present invention;

FIGURES 2 and 3 are fragmentary views showing the calender rolls in various stages of lifting and showing the cooperation between the lift arms and the pressure applying and relieving mechanism for varying the pressure between the nips of the calender rolls; and

FIGURE 4 is a fragmentary horizontal sectional view taken through a frame member of the calender stack substantially along line IVIV of FIGURE 1.

In the embodiment of the invention illustrated in the drawings, I have shown in FIGURE 1 a calender stack it), comprising a pair of spaced upright posts 11, suitably connected in parallel spaced'relation with respect to each other. The posts 11 are shown in FIGURE 4 as being hollow and extend upwardly from a base 12 extending forwardly of said posts and having bearing supports 13, 13 extending upwardly therefrom, forming bearing supports for a bottom or king roll 15. Extending above the bottom roll 15 and supported on said roll is a series of superposed calender rolls 16, 15, the centers of said rolls being alternately offset from one side to the other of the vertical axis of the bottom roll 15, to provide a series of pressure nips between said calender rolls and in nip defining relation with respect to the bottom roll 15.

The bottom roll 15 serves as a finishing roll and is the driven roll of the calender stack. The roll 15 may be driven from a suitable source of power in a conventional manner (not shown) and may have a plated surface, plated with chrome or nickel, to provide a highly polished surface where the calender stack is used for glossing treatment. The superposed rolls 16, 16 are driven by contact with a Web W and the bottom roll 15, although they may be positively driven if desired.

The rolls 16, 16 are of a similar construction and are each mounted on the posts 12, 12 in a similar manner so the mounting of one roll only need herein be shown and described in detail.

Each roll 16 is journalled at its opposite ends in bearing housing 17, 17 mounted on the outer ends of lift arms 19, 19, transversely pivoted to the posts 11, 11 and extending through said posts rearwardly of the rear ends thereof, and also extending in advance of said posts and having the bearings housing 17, 17 suitably supported on the free ends thereof. Each lift arm 19 is trunnioned in advance of the post 11 between bearing brackets 21, 21 mounted on the forward end portions of the posts and extending forwardly therefrom. A trunnion pin 22, journalled at its ends in the trunnion brackets 21, 21, is provided to trunnion the associated lift arm 19 to the trunnion brackets 21, 21. Each lift arm 1? extends between spaced facing channel-like sections 23, 23 of the column 11, beyond the rear end of said column, and has an upper pressure plate 24 extending along the rear end portion thereof, and a parallel spaced lower pressure plate 25 in ali nment with said upper pressure plate.

A means is provided to pivot the lift arms about the axes of the trunnion pins 22 and lift the calender rolls out of engagement with each other, which as herein shown comprises two parallel spaced bars 26 guided for vertical movement along the associated column 11. Each bar 26 is guided in a groove 27 formed in a leg 28 of the channel 23. The groove 27 is formed by a recessed portion extending along the end of the leg 28 and by an inner face 29 of a leg 3% of a bracket 31, for a load lever 33. As shown in FIGURE 4 the bracket 31 extends along opposite sides of the load lever 33 and abuts the rear end portions of the channel-like members 23 of the column 11, and is secured thereto as byT-bolts 35 and nuts 36 threaded thereon.

The lifting bars 26 have a series of vertically spaced pins 37 connected therebetween and mounted in said lifting bars at their opposite ends. The pins 37 may be progressively spaced closer together from the tops of the bottoms of said lifting bars to first engage the pressure plate 24 of the top calender roll 16 and then progressively engage the lower pressure plates to effect succes- 'sive raising of said calender rolls from the top to the bottom of the calender stack upon downward movement of the lift bars 26. I H H p The lifting bars 26 may be Simultaneously moved in a downward direction to successively lift the calender rolls 1'6, 16 by "operation of a threaded shaft 39 extending upwardly of a screw jack 40. The screw jack ltl may be of any well known form. A screw jack 30 is provided 'on each side of the frame for the calender stackand may be simultaneously driven from a common source of power, to simultaneously operate said screw jacks to lower the lifting bars 26 along each column 11 at the same rates ofspeed. The threade'd'shafts may be suitably secured to blocks 41 connected between the lowerends ofthe lifting bars 25, 26, to effect raising and lowering of said bars upon operation of saidjacks, V I

Referring now in particular to the means for increasing or relieving the nip pressures between the calender rolls 16, 16 and the bottom calender roll and the king roll 15, to maintain the exacting nip pressures required for calendering paper, the load levers 33 are provided to increase or decrease the nip pressures independently of the lifting bars 26, 26. The load levers 33 are of generally C-shaped form s, opening in a direction away from the column 11, and are transversely pivoted to the brackets 31 between the legs thereof on transverse pivot pins 43. Each bracket 31 has an abutment 44 formed integrally with the outer endportions of the legs 30 and, disposed between vertically spaced abutment plates 45 of the associated load lever 33. Fluid pressure operated diaphgrams 46 which maybe in theformof commercial Airide springs are interposed between'o'pposite sides of the abutment 4 and the abutment plates '45, and serve to pivot the associated load lever 33 about the axis of the pivot pin 43. The diaphragms 46, 46 may be independently supplied with fluid under pressure, such as air, to pivot the load lever 33 in one direction or another and thereby pivot the lift arms 19 in directions to relieve the'ca'lender rolls from the weight of the bearing housing 17 or to increase the nip pressure between the calender rolls. The'di aphrjagms 46, 46 may be supplied with air under pressure under the control of suitable yalves, which are no part of the present invention so need not herein be shown'or described further.

Eachload lever 33 has a backbone 47 having a recessed portion '43 opening toward the lift arm 19 and extending over the pressure plates 24 and 25. As shown hi l- 1G- URES Z, 3 and 4, the recessed portion 48 terminates at its upper and lower ends into pressure nibs 49 and 50, 'engageable with the upper and lower pressure plates 24- and "25 respectively. The lower pressure nib terminates at its'end facing the lift lever 19 into an inclined camming surface 51 extending downwardly therefrom and inclined toward the lift bars 26. The upper and lower pressure plates 24 and 25 have antifriction members, such as balls 53, recessed therein engaging the lower pressure nib 50 andfcamming the load lever 33 in a direction, which in FIGURES 2 and 3 is a counterclockwise direction, and enabling the lift lever to be moved by the pins 37, 37 to lift the calender rolls 116, 16 to their extreme lifted positions shown in FIGURE 4 without interference with the load levers 33. v, ,p w 7 M H Thus as fluid under pressure is admitted to the upper diaphragm 46, the load lever 33 will be pivoted in a direction, which in FIGURE 2 is a counterclockwise direction, and bring the nib 4 9 into engagement with the upper pressure plate 24. This will pivot the associated lift arm 19 about the axis of the pivot pin .22 in a clockwise direction, and relieve the associated calender roll 16 from the weight of the bearing housings l7 and the bearings housed therein, and will thereby reduce the nip pressures between the calender rolls and between the 'lower calender roll and the bottom finishing roll 15.

As fluid under pressure, such as air, is'admitted to the lower diaphragm 46, the load lever .33 will be pivoted in a clockwise direction and engage the nib 59 with the l lower pressure plate 45, and pivot the lift arm 19 in a clockwise direction to increase the pressure of the associated calender roll 16 against its next lower calender roll and thereby increase the nip pressures,

It may be seen from FIGURE-S 2 and 3 that when the lift bars 26 are moving downwardly to lift the calender rolls 16 out of engagement with each other as the lift pins 37 come into engagement with the upper pressure plates 24 and pivot the lift arms in a counterclockwise direction, that a ball 53 on the lower pressure plate 25 will come into engagement with the pressure nib 5i) and pivot the load lever 33 in a counterclockwise direction, collapsing the lower diaphragm 46 and extending the upper diaphragm 46. As lifting movement of the lift lever 19 continues, a ball 53 in the lower pressure plate 25 will ride downwardly along the inclined cam surface 51 and continue the camming of the load lever in a clockwise direction. As the lower ball 53 comes out of engagement with the camming surface 51 the ball 53 in the upper pressure plate 24 will continue camming movement of the load lever 33 in a counterclockwise direction and thereby accommodate free lifting movement of the associated calender roll, without interference with the load relieving or pressurizing mechanism. a

It should here be noted that when the calender rolls 15 are in their extreme lifted positions, the lower diaphragms 46 are completely collapsed. The diaphragms, however, are so designed as to be collapsed without injury to the diaphragms, and the spacing between the pressure plates and the abutment 44 is such that when the diaphragms are in their collapsed positions, the lower pressure plates 45 will be out of engagement with the lower abutment 44, so as to avoid injury to the diaphragms I mounted therebetween.

It may be seen from the foregoing that a simple and improved form of calender stack has been provided having a nip relieving and loading device separate from the lifting device for the calender rolls, and relieving the loads between the calender rolls as well as increasing the loads therebetween to provide the exacting nip pressures required for calendering and that the lifting and load applying mechanism is so arranged as to accommodate free lifting of the calender rolls by camming the nip relieving and loading devices out of the way of the lift bars and pins for the associated calender roll, during raising thereof. The calender rolls may thus be finely adjusted to the required nip pressures, and the raising mechanism for the calender rolls, cam the pressure adjustment mechanism out of the way and thereby provide the freedom to raise the calender rolls without binding with the load adjusting mechanism.

While I have herein shown and described one form in which my invention may be embodied, it may readily be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof, as defined by the claims appended hereto.

I claim as my invention:

1. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll rotatable about a stationary horizontal axis and a plurality of superposed rolls rotatable about vertically movably axes, separate and independent bearings for supporting opposite ends of said superposed rolls, anindividu'al lift lever supporting each bearing, means pivotally mounting said lift levers to said frame for movement about axes parallel to the axes of rotation of said rolls and extending transversely of said lift arms, a pivoted load lever in association with each lift lever having facing engaging surfaces engageable with opposite sides of said lift arm, and fluid pressure operated means for moving said load levers in one direction to engage the associated lift arms and pivot said arms in a direction to relieve the calender rolls from the weight of the support of the bearings therefor and to move said load levers to engage opposite sides of said lift arms and move said lift arms in a direction to increase the nip pressures between said calender rolls.

2. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame, including a bottom roll rotatable about a horizontal axis fixed from vertical movement and a plurality of superposed rolls, separate and independent bearings for supporting the ends of said superposed rolls, an individual lift arm supporting each bearing, means pivotally mounting said lift arms on said frame intermediate their ends for movement about axes parallel to the axes of rotation of said rolls, and means pivoting said lift arms in opposite directions to increase or decrease the pressure in the nips between said calender rolls comprising an individual load lever in association with each lift arm and engageable with the opposite ends of said lift arms from said bearings, and pivotally mounted on said frame for movement about axes parallel to the axes of pivotal movement of said lift arms, said load levers having spaced engaging faces engageable with the opposite sides of said lift arms, and fluid pressure operated means pivoting said load levers in one direction to relieve the pressures between the nips of said calender rolls and in an opposite direction to increase the pressure between the nips of said calender rolls.

3. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably sup ported in said frame including a bottom roll and a plurality of superposed rolls supported thereon, fixed bearing supports for opposite ends of said bottom roll, separate and independent bearings supporting opposite ends of said superposed rolls, an individual lift arm supporting each bearing, means pivotally mounting said lift arms on said frame intermediate their ends, and means pivoting said lift arms in opposite directions to increase or decrease the pressure in the nips between said calender rolls comprising an individual load lever in association with each lift arm, an individual bearing support for each load lever having an abutment thereon, fluid pressure diaphragrns mounted on opposite sides of said abutment and engaging the associated load lever for moving said load lever in opposite directions to increase or decrease the nip pressures between said calender rolls, each load lever also having spaced facing engaging nibs for engaging opposite sides of said lift arm, to pivot said lift arm in opposite directions.

4. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls, fixed bearing supports for opposite ends of said bottom roll, separate and independent bearings for supporting opposite ends of said superposed rolls, an individual lift arm supporting each bearing, power means for positively lifting said lift arms to lift said calender rolls out of engagement with each other, and other means engageable with said lift arms for exerting nip relieving and nip applying pressure thereon, said last mentioned means having camming'surfaces thereon engaged by said lift arms and cammed by said lift arms out of the way of said lift arms, and thereby accommodating the free raising of said lift arms to positively disengage said calender rolls.

5. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls, stationary bearing supports for opposite ends of said bottom roll, separate and independent bearings for supporting opposite ends of said superposed rolls, an individual lift arm supporting each bearing, means pivotally mounting said lift arms on said frame for movement about axes parallel to the axes of said calender rolls, means movable along said frame and engageable with said lift arms for positively lifting said calender rolls out of engagement with each other, an individual load lever associated with each lift arm, fluid pressure operated means for operating said levers to engage the associated lift arms and pivot said arms in one direction to relieve pressure between the nips of said calender rolls and in an opposite direction to apply pressure between the nips of said calender rolls, said load levers having spaced engaging surfaces extending above and below said lift arms into positions to engage said arms, and camming surfaces extending from one of said engaging surfaces and engaged by said lift arms upon lifting movement of the calender rolls and camming said load levers out of interfering engagement with said lift arms.

6. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls supported thereon, fixed bearing supports for opposite ends of said bottom roll, separate and independent bearings for supporting the ends of said superposed rolls, an individual lift arm supporting each bearing, means pivoting said lift arms to said frame intermediate their ends, means engageable with said lift arms for positively lifting said arms and said calender rolls out of engagement with each other, and other means engageable with said lift arms for exerting nip relieving and nip applying pressures on said lift arms including an individual load lever for each lift arm, each load lever having vertically spaced engaging surfaces engageable with opposite sides of the associated lift arm, fluid pressure operated means for pivoting said load levers in opposite directions, said vertically spaced engaging surfaces of said load levers being engageable with opposite sides of said lift arms and exerting pressure thereon in pressure relieving and pressure applying directions, the lower of said engaging surfaces having a camming surface extend ing downwardly therefrom engaged by the associated lift arm upon lifting movement thereof, and camming said load lever out of the way of said lift arm.

7. In a paper machine, a multi-nip calender comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls supported thereon, stationary bearing supports for opposite ends of said bottom roll, separate and independent bearings for supporting the ends of said superposed rolls, an individual lift arm supporting each bearing, means pivoting said lift arms to said frame intermediate their ends, means engageable with said lift arms for positively lifting said arms and said calender rolls out of engagement with each other, and other means engageable with said lift arms for exerting nip relieving and nip applying pressures on said lift arms including an individual load lever for each lift arm, each load lever having vertically spaced engaging surfaces engageable with opposite sides of the associated lift arm, fluid pressure operated means for pivoting said load levers in opposite directions, said load levers having vertically spaced engaging surfaces engageable with opposite sides of said lift arms and exerting pressure thereon in pressure relieving and pressure applying directions, the lower of said engaging surfaces having. a camming surface extending downwardly thereof engaged by the associated lift arm upon lifting movement thereof, and camming said load lever out of the Way of said lift arm, and said lift arms having hardened anti-friction members engaging said camming surfaces.

8. A multi-nip calender stack comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls supported thereon, stationary bearing supports for opposite ends of said bottom roll, separate and independent bearings for supporting opposite-ends of said superposed rolls, an individual lift arm supporting each bearing and pivotally mounted on said frame for movement about an axis parallel to the axis of the associated calender roll and intermediate the ends of said lift arm, each lift arm having upper and lower pressure plates extending along the endportions thereof opposite from said bearings, an individual load lever in association with each lift 'arm and the upper and lowerrbearing surfaces thereof, each load lever having vertically spaced abutment surfaces and being pivoted to said frame intermediate said abutment surfaces for movement about an axis parallel to the axis of the associated lift arm, a stationary abut me'nt extending between said abutment surfaces, fluid pressure operated diaphragms seated on opposite sides of said stationary abutment and on said abutment surfaces for pivoting said load lever in opposite directions upon the admission of fluid under pressure to one or the other of said 'diaphragms, said load lever also having spaced pressure surfaces on the oppositesides thereof from said abutment surfaces, and extending above and below said pressure plates and engageable therewith to move said lift arm in load relieving and load applying directions, and a camming surface extending downwardly from the lower of said pressure surfaces and cammed by the end of said lift arm adjacent said pressure plate to accommodate free lifting movement of said lift arms and the calender rolls carried thereby.

9. A 'multi-nip calender stack comprising a calender frame, a stack of calender rolls movably supported in said frame including a bottom roll and a plurality of superposed rolls supported thereon, stationary bearing supports for opposite ends of said bottom roll, separate andindependent bearings for supporting opposite ends of said superposed rolls,fan individual lift arm supporting each bearing and pivotally mounted on said frame for movement about an axis parailel to the axis of the associated calender roll and intermediate the ends of said lift arm, each lift arm having upper andlower pressure plates extending along the end portions thereof opposite from said bearings, an individual load lever in association with each lift arm and the upper and lower bearing surfaces thereof, each load lever having vertically spaced abutment surfaces and being pivoted to said frame intermediate said abutment surfaces for movement about an axis parallel to the axis of the associated lift arm, a stationary abutment extending between said abutment surfaces, fluid pressure operated diaphragms seated on opposite sides of said stationary abutment and on said abutment surfaces for pivoting said load lever in opposite directions upon the admission of fluid under pressure to one or the other of said diaphragms, said load lever also having spaced pressure surfaces on the opposite side thereof from said abutmentsurfaces, and extending above and below said pressure plates and engageable therewith to move said lift arm in load relieving and load applying directions, spaced balls carried by said lift arms and extending rearwar-dly of said bearing plates, and a camming surface extending downwardly from the lower of said pressure surfaces and engaged by said balls and accommodating balls to earn said load levers out of the way of said lift arms and accommodate free vertical movement of said lift arms and the caiender rolls carried thereby.

her-assess Cited in the file or this "patent UNITED STATES PATENTS 2,638,383 Tuniey May 12, 1953 2,-sso,9s2 Hornbostel se r. 9, 1958 2,971,457 new Feb. 14, I961 

1. IN A PAPER MACHINE, A MULTI-NIP CALENDER COMPRISING A CALENDER FRAME, A STACK OF CALENDER ROLLS MOVABLY SUPPORTED IN SAID FRAME INCLUDING A BOTTOM ROLL ROTATABLE ABOUT A STATIONARY HORIZONTAL AXIS AND A PLURALITY OF SUPERPOSED ROLLS ROTATABLE ABOUT VERTICALLY MOVABLY AXES, SEPARATE AND INDEPENDENT BEARINGS FOR SUPPORTING OPPOSITE ENDS OF SAID SUPERPOSED ROLLS, AN INDIVIDUAL LIFT LEVER SUPPORTING EACH BEARING, MEANS PIVOTALLY MOUNTING SAID LIFT LEVERS TO SAID FRAME FOR MOVEMENT ABOUT AXES PARALLEL TO THE AXES OF ROTATION OF SAID ROLLS AND EXTENDING TRANSVERSELY OF SAID LIFT ARMS, A PIVOTED LOAD LEVER IN ASSOCIATION WITH EACH LIFT LEVER HAVING FACING ENGAGING SURFACES ENGAGEABLE WITH OPPOSITE SIDES OF SAID LIFT ARM, AND FLUID PRESSURE OPERATED MEANS FOR MOVING SAID LOAD LEVERS IN ONE DIRECTION TO ENGAGE THE ASSOCIATED LIFT ARMS AND PIVOT SAID ARMS IN A DIRECTION TO RELIEVE THE CALENDER ROLLS FROM THE WEIGHT OF THE SUPPORT OF THE BEARINGS THEREFOR AND TO MOVE SAID LOAD LEVERS TO ENGAGE OPPOSITE SIDES OF SAID LIFT ARMS AND MOVE SAID LIFT ARMS IN A DIRECTION TO INCREASE THE NIP PRESSURES BETWEEN SAID CALENDER ROLLS. 